GloFish
Glofish are genetically modified zebrafish (Danio rerio) that were made to fluorescently glow. They are the first commercialized genetically modified organism to be sold to people. There are currently 6 different colors that are available from Yorktown Technologies, L.P and they are Starfire Red®, Electric Green®, Sunburst Orange®, Cosmic Blue®, Galactic Purple®, and Moonrise Pink™. Glofish today are bred and they maintain their color throughout life and pass it down to their offspring. Genetic Modification - How they are made Glofish are zebrafish that have been genetically modified to display different to the unaided eye in either daylight or under UV light. First discovered by Dr. Zhiyuan Gong, green was the first color to be successfully displayed. After his initial success, other colors soon followed. To do this, scientists isolated green fluorescent protein (GFP) from the jellyfish (Aequorea victoria). They then made chimeric DNA constructs with a zebrafish gene promoter such as the myosin light chain 2 (MLC2f) gene. The DNA construct is inserted into either the 1st or 2nd cell stage of embryonic growth by microinjection. The fish were allowed to grow and because of the skeletal muscle promoter, the fluorescent gene was allowed to be transcribes and translated to produce the protein. In the case of this DNA construct, the fluorescence was expressed in skeletal muscles. After discovering that zebrafish can be made to fluoresce green, Dr. Zhiyuan Gong soon created other colors such as yellow and red. To create the other colors, the cDNA for the initial green fluorescent protein was mutated by site directed mutagenesis. The products of this procedure produced yellow fluorescent protein (YFP), blue fluorescent protein (BFP), and cyan fluorescent protein (CFP). The red fluorescent protein was found from an IndoPacific sea anemone relative (Discosoma sp). Original Goals Originally the zebrafish were made to fluoresce for the detection of pollution in waterways. This was accomplished as they were tested using different pollutants and showed to fluoresce when they came into contact with those pollutants. The fish were constructed so that the transgenic zebrafish carry pollution-inducible response elements. When the fish encounter these pollutions, the pollutions become concentrated in their tissues which induce the response elements engineered into the fish. Once the response elements are induced, they upregulate the expression of the gene that code for the green fluorescence protein. The fish that glow green will show that there are pollutants in the water whereas fish that do no glow show clean water. Future - Commercial When these fish were shown to the public however, they took off as a nice ornamental decoration for the house as now they are commercially available. The Glofish Website can show you where to buy these inexpensive fish. References 1. Glofish Website 2. Glofish Wiki 3. GloFish, The First GM Animal Commercialized: Profits Amid Controversies 4. Development of transgenic fish for ornamental and bioreactor by strong expression of fluorescent proteins in the skeletal muscle 5. Transgenic Zebrafish as Sentinels for Aquatic Pollution 6. Chimeric Gene Constructs for Generation of Fluorescent Transgenic Ornamental Fish